报告题目：On essential spectra and essential numerical ranges of Hamiltonian systems

报告人：山东大学  孙华清 教授

报告时间：18：30-21：30, 1^th July 2022.

报告地点：腾讯会议 (ID:404 451 812) 联系人：田信宽(Tel:18769092104)

Abstract：

This talk is concerned with essential numerical ranges and essential spectra of Hamiltonian systems with one singular endpoint. For semi-bounded systems, the characterization of each element of the essential numerical range in terms of certain singular sequences is given, the concept of form perturbation small at the singular endpoint is introduced, and the stability of the essential numerical range is obtained under this perturbation, which shows that the stability of the infimum or supremum of the essential spectrum. Some sufficient conditions for the invariance of the essential numerical range are given in terms of coefficients of Hamiltonian systems.

简介：

孙华清，山东大学教授、博导，一直从事奇异微分与差分算子谱理论研究，在“J. Funct. Anal.”，“J. Differential Equations”，“Proc.Roy. Soc. Edinburgh Sect. A”，“Math. Nachr.”等国际权威杂志上发表27篇SCI收录的论文，先后主持国家自然科学基金3项，其它省部级项目多项。